Inferior vena cava (IVC) filters are small, expanding filters commonly inserted into the inferior vena cava to prevent pulmonary embolism (see FIG. 1). Retrievable filters may feature a hook on the apex to allow for removal, though non-retrievable filters are sometimes used. Because the risk of embolism is often short-term, removal of the filters is often indicated in hopes of reducing complications such as filter migration or perforation of the vessel wall. However, while placement rates have been steadily increasing, retrieval rates remain low.
The use of inferior vena cava (IVC) filters for therapeutic and prophylactic indications has tremendously increased over the past decade. The majority of the IVC filters placed are retrievable and can be removed when the risk of pulmonary embolism decreases. However, many IVC filters are not retrieved. On the other hand, there are increasing number of case reports of long-term complications of leaving indwelling IVC filters, including IVC thrombosis, filter migration, fracture, and penetration into adjacent structures. These complications require additional endovascular and sometimes open surgeries and are a source of significant morbidity and mortality for the patients and costs on the health care system. As a consequence, the Food and Drug Administration issued an alert to vascular specialists to remove IVC filters from patients in whom protection from pulmonary embolism is no longer needed.
The retrieval of an IVC filter can be a simple and short procedure performed with a snare and a co-axial sheath. Most retrievable filters have a conical design with a hook at the apex that allows snaring the device from above through a jugular access. The vena cava is accessed from the internal jugular vein at the neck, which leads straight past the heart and kidneys to the deployed filter. Using 2D fluoroscopy, the clinician will attempt to snare a roughly 2 mm hook on the apex of the filter and pull it into a sheath for removal. After snaring the hook, a sheath is advanced over the snare to collapse the device and retrieve it. However, this procedure can become very challenging when it is attempted after a long duration from the time the IVC filter was inserted. The struts become incorporated and scarred and are hard to pull out. In some cases, the IVC filter is tilted and the hook cannot be snared. Also, filters can deploy tilted, resulting in the hook resting against the vessel wall. As fibrous tissue builds around this, snare-based retrieval can become difficult or impossible.
Several techniques have been described to allow “difficult” IVC filter retrieval such as the dual-access technique, the balloon-displacement technique, and the sandwich technique among others. The need to “micro-dissect” the fibrotic tissue around the struts is well recognized and has led to the use of unconventional tools by some operators such as rigid bronchoscopy forceps or laser sheath. Even though there is literature reporting success in using those instruments, the safety and effectiveness are not established especially in that they were not designed to retrieve IVC filters.
U.S. Patent Publication Nos. 2002/0045918 and 2014/0031854 illustrate known IVC filter removal devices. However, such devices are only able to move longitudinally relative to the device (e.g. the handle) itself and/or the vessel in which it is positioned as neither describe or suggest any type of articulation (i.e. side to side movement) as disclosed and claimed herein.